Murder on the Orient Express by Agatha Christie (Fontana, 1959)

Found on a stall at Fishermen's Wharf Markets in Port Adelaide:

 

Thundering along on its three days' journey across Europe, the famous Orient Express suddenly comes to a stop in the night.

Snowdrifts block the line somewhere in the Balkans.  Everything is quiet and passengers quickly settle down for the night, including Hercule Poirot.

In the morning an American millionaire is found stabbed, many times--Poirot is very much wanted.  The untrodden snow seems to prove that the murderer is still on board.  Poirot begins to think--and a brilliantly ingenious solution is found...

 And without a doubt, the solution is brilliant ingenious.  (No, I'm not going to tell you what it is.  This blog is a Spoiler Free Zone!  If you haven't already read Murder on the Orient Express--one of Christie's best known books--do so and find out the solution for yourself.)

This is the sort of plotting that earned Agatha Christie the sobriquet "the Queen of Crime".  At times her prose was merely functional, her characters two-dimensional, her attitudes snobbish and old-fashioned.  She was never adverse to using stereotypes, particularly when depicting foreigners or members of the lower classes.  However, she knew how to weave together the real clues and red herrings to create a mystery that kept the reader guessing right to the end.